Medical Management of Advanced Oxalate Nephropathy Secondary to Gastric Bypass Surgery

A 73-year-old Caucasian female with a history of obesity status post Roux-en-Y gastric bypass (RYGB) surgery presented with generalized weakness and was found to have acute kidney injury (AKI) with a creatinine peak of 9.1 mg/dL above her baseline of 1.2 mg/dL, and anemia with hemoglobin 5.7 g/dl. Kidney biopsy revealed oxalate nephropathy likely related to gastric bypass surgery four years prior. RYGB is a strong risk factor for hyperoxaluria, nephrolithiasis, and oxalate nephropathy which often progresses to end-stage renal disease (ESRD). Meaningful treatment strategies for this disease entity are lacking. We present a case in which dietary and pharmacological management without the use of renal replacement therapy resulted in stabilization of chronic kidney disease (CKD) stage 5 for seven years at the time of this writing.